Originally puublished in 1915. PREFACE: The extensive use and increasing popularity of centrifugal pumping machinery make it necessary for many to become familiar with this subject in all its phases. In this book an effort has been made to cover the following ground To illustrate and explain all the essential features of construction of modern centrifugal pumps, to present a clear and intelligible theory which shall be entirely general in its nature, to explain by this theory the pump characteristics and connect the theory with the actual facts, to present a thorough discussion of the factors affecting efficiency, to considerthe characteristics of varioustypes ofpumps and their suitability for different services, to compare centrifu- gal with displacement pumps, and to present various general laws and factors leading to a better appreciation of the field of service of such pumps and a better means of selecting the proper combinations. While this is not primarily a book on design, it is believed that a thorough study of the foregoing will be of value to prospective designers, and in addition the methods of design of centrifugal pumps are outlined. The material in this book is based upon a study of the performances of 123 turbine and 51 volute centrifugal pumps made by 17 and 12 different companies respectively. The field covered by them ranged from 1 to 11 stages, heads from 7 to 1843 ft., capacities from 108 to 132,000 gal. per minute, speeds from 62 to 20,000 r.p.m., and efficiencies from 30 to 87 per cent. A considerable portion of the work is also founded upon the anal- ysis of tests made by the author upon a volute pump and a turbine pump for both of which all information regardingdimensions and other quantities was obtainable. With the turbine pump an extensive and accurate series of tests was made at various speeds from 700 to 2,000 r.p.m. Both of these pumps were regular commercial pumps of good design, not freak pumps built for experimental purposes only. The author has drawn upon trade catalogues and several books and papers for much of his material, due credit for which is given in the text, but it is believed that a very great deal of the following treatise will be found to be new. The common usage regarding terms employed has been followed as far as possible, but in cases where there were no precedents or where the usage was illogical and confusing, new terms have been created. It is hoped that eventually some of these things may become standardized. The book has been so written as to serve the needs of the practising engineer who wishes to obtain a grasp of this subject. By the insertion of problems and questions it is believed that it will be found equally well adapted for use as a text. Contents include: PREFACE v CHAPTER I INTRODUCTION 1 Definition Classification Reaction turbine vs. turbine pump Historical development Conditions of use Pump size Rated head and discharge…